OTTAWA (Reuters) - Canada has stopped its electronic spy agency from sharing some data with key international allies after discovering the information mistakenly contained personal details about Canadians, government officials said on Thursday.

Ottawa acted after learning that the Communications Security Establishment (CSE) agency had failed to properly disguise metadata - the numbers and time stamps of phone calls but not their content - before passing it on to their international partners.

"CSE will not resume sharing this information with our partners until I am fully satisfied the effective systems and measures are in place," Defense Minister Harjit Sajjan said in a statement.

Sajjan, who has overall responsibility for the agency, did not say when Canada had stopped sharing the data in question.

Canada is part of the Five Eyes intelligence sharing network, along with the United States, Britain, Australia and New Zealand. CSE, like the U.S. National Security Agency (NSA), monitors electronic communication and helps protect national computer networks.

While the agency is not allowed to specifically target Canadians or Canadian corporations, it can scoop up data about Canadians while focusing on other targets.

Sajjan, blaming technical deficiencies at CSE for the problems, said the metadata that Canada shared did not contain names or enough information to identify individuals and added: "The privacy impact was low."

He made the announcement shortly after an official watchdog that monitors CSE revealed the metadata problem. The watchdog said CSE officials themselves had realized they were not doing enough to disguise the information they shared.

An NSA program to vacuum up Americans' call data was exposed publicly by former NSA contractor Edward Snowden in 2013 and prompted questions about the CSE's practices.